Heat exchanging apparatus



March 29, 1932. R j- WAT-r HEAT ExcHANGING APPARATUS Filed Nov. 3.119302 Sheets-Sheet Fuga. G

will/lll mm V/ll//hW/l//l/ mm '/ll/l//A'l March 29, 1932. R. J. wATT1,851,881

HEAT EXCHANGING APPARATUS Filed Nov. 5, 1930 2 Sheets-Sheet 2 PatentedMar. 29, 1932 UNITED" STATES ROBERT JARDINE WATT, F NORTH FERRIBY,ENGLAND,

HEAT` EXCHANGING APPARATUS Application 'filed November 3, 1930,"Seria1No. 493,180, and in Great Britain April 4, 1930.

This invention has relation to heat exchanging apparatus and moreparticularly to cooling apparatus for the abstraction of heat fromliquids. Its principal object is to provide an efficient heat exchangerespecially a cooler, which can be made of a formation offering theminimum resistance to the flow of fluid and with a surface the whole ofwhich constitutes useful heat exchanging area.

i0 A further object of the invention is to pro-V These and other objectswill appear moreVv fully from the following specific description of twoembodimentsof the invention. In the accompanying drawings Fig. l is anend elevation of a cooler of stream-line formation, one end plate beingremoved to reveal the interior;

Fig. 2 is a longitudinal section on the line II-II of Fig. l;

Fig. 3 is a plan View of the inner side of a cooler adapted to form partof a surface;

Fig. 3a is a plan view of the inner side at the opposite end portion ofthe cooler of Fig 3.

Fig. 4l is a cross section thereof; Fig. 5 is an end elevation of aheader employed in the cooler of Figs. 3, 3a., and 4; and

Fig. 6 is a plan View of said header.

In the embodiment of the invention illustrated in Figs. l and 2, plates1,12 of a streamline contour forming adjacent walls of inlet and outletheaders 3, 3a., l are connected at their peripheries to opposite edgesof a corrugated sheet 5 bent to said stream-line contour. Theperipheries of said plates l, 2 are crenellated to fit the corrugations.The pcripheries of plates 6, 7 forming the outer wallsl of the headers3, 3a, 4 are connected to the edges of a smooth metal sheet 8 which isalso bent to the same stream-line contour and forms the remaining wallsof said headers. The smooth sheet 8 is connected to the corrugated sheet5 along the crest of each corrugation, producing a series of fluid ducts9 communicating between the headers 3, 3a. 4. The remaining edges of thesheet 5 and the sheet 8 are connected together in the trailing edge ofthe stream-line shape. The inlet header 3 is fitted with an inlet pipel0 for the fluid to be cooled and the outlet header 4 with an outlet orreturn pipe l1 for the cooled fluid. The whole structure is carried by atubular support 12 to which the plates 1, 2, 6, 7 are secured where theyare penetrated thereby. The various parts may be secured or connectedtogether by welding, brazing, sweating and the like as circum- 7 stancesrequire. If preferred the corrugated and smooth sheets 5, 8 may each beintwo parts joined both at the leading and trailing edges of thestream-line shape.

The cooler as a whole thus has a streamline formation bounded by thesmooth 'metal' sheet or skin 8. Accordingly it may4 form part of or beincorporated in an aerofoil,y strut, fairing and the like. In. any casethe stream-line formation, in addition toits own advantage of `reducingresistance and drag, ensures that the whole surface of the sheet 8 isair-swept and fully effective as heat exchanging area, the boundarylayer effect being reduced to a minimum.4 The efficiency of the heatexchanger is enhanced by the fact that heat is transmitted by conductionfrom the trough-parts of the corrugated sheet 5 to the exposed face ofthe smooth sheet 8.

The shapeand size of the duct-s 9 are designed to furnish an aggregateheat exchange area sufficient to ensure the required temperaturereduction of the fluid to be cooled in its passage, at a given rate offlow, through said ducts from the inlet header 3 to the out- 95 letheader 4. Naturally the precise design of the cooler will depend alsoupon the nature of the fluid cooled, for example, oil, Water, steam andthe like. Provision may bemade for regulating the cooling action loosurface.

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f in said stream-line body and between said partition walls,.and inletand outlet conl'iectlons either by shrouding or by the inclusion in theinlet pipe lline of a multi-way cock whereby a part or the whole of thefluid which would pass through the cooler may be short circuited to thereturn pipe line.

The form of cooler illustrated in Figs. 3 to 6 is more particularlydesigned to occupy a part of a surface which is in a fluid stream, thatis, a covering for an aerofoil, nacelle, fuselage, boathull or the like,the cooler being shaped in conformity with said In the exampleillustrated the smooth sheet 8 constituting the outer or heat transferwall and the corrugated sheet 5 forming the ducts 9 are of a planeformation. Obviously, however, they can be shaped to form a part orcontinuation of a surface of any desired kind. To enhance the strengthand fluid-tightness of the cooler, the edges 13 of the sheet 8 arefolded over the edges of the sheet 5 as shown in Fig. 3 and Fig. 3a.Fig. 4 shows the edges 13 before being so folded. The inlet and outletheaders 3, 3a, 4 each consist of a single-piece, bottomless body fittedrespectively with an inlet and outlet pipe 10, 11.. The bottom walls ofthese headers are provided by the sheet 8 when said header bodies aresecured thereto. As before, the adjacent sides 1, 2 of the headers 3,3a, 4 are connected to the corresponding edges of the corrugated sheet5, the edges of said sides 1, 2 being crenellated in conformity with thecorrugations to permit communication between 'the ducts 9 and the headers. Tongues 14 are formed at intervals along the sides 1, 2 and,projecting at right angles to said sides into the troughsbetween theducts, facilitate the making of a good Huid-tight and mechanical Aroundthe other sides. the headers 3, 3a, 4 are provided with a Range 15 overwhich the edges 13 of the smooth plate 8 are also folded, said edgesbeing finally sealed all around by,

for'example, sweating. The inlet and outletV Y' pipes 10, 11 beingarranged at the ends of the headers 3, 3a, 4, said headers are madetapered. as illustrated, a substantially uniform distribution of thefluid to be cooled Y between the ducts 9 being thereby obtained.

In other respects the construction and action of this cooler are similarto those of the cooler of Figs. 1 and 2.

VVhat I claim is 1- i 1. Cooler comprising a smooth sheet metal body ofstream-line formation, plates closing thev sides of said stream-linebody, partition walls arranged within said body parallel to said vsidesto 'divide off header spaces therein, a corrugated sheet metal bodyarranged withto said header spaces for fluid to be cooled,the crests ofthe corrugated sheet metal body be- Y ing connected to the smooth sheetmetal body connection.

to form a series of fluid-ducts communicating between the header spaces.

2. Cooler comprising a smooth metal sheet, [lat bottomless bodies laidflat upon and secured to one face of said sheet along opposite edgesthereof to form inlet and outlet headers, inlet and outlet fluidconnections to said headers, and a corrugated metal sheet secured to thesame face of said smooth metal sheet between said headers, the crests ofthe corrugated metal sheet being connected to the face of the smoothsheet to form a series of fluidducts communicating between the headers.

3. Cooler as claimed in claim 2, wherein the headers each consist of abottomless body of a tapered formation having a crenellated edge forconnection to the corrugated metal sheet.

4. Cooler comprising a smooth heat exchanging wall exposed on one faceto a cooling fluid, inlet and outlet headers bounded on the outside bytransverse walls extending along opposite edges of said heat exchangingwall and on the inside by transverse walls extending `across said heatexchanging wall at a distance from the outside walls, and a corrugatedwall secured to the other face of the heat exchanging wall and extendingbetween the inside walls of the headers, the corrugations therebyforming a series of fluid ducts communicating in parallel between saidheaders.

5. Cooler comprising a smooth heat exchanging wall having one faceexposed to a cooling fluid, inlet and outlet headers bounded on theoutside by transverse walls secured to opposite edges of the other faceof said heat exchanging wall and on the inside by crenellated transversewalls extending across said other-face of the heat exchanging wall at adistance from the outside walls, and a corrugated wall havingthe crestsof its corrugations secured to the aforementioned other face of the heatexchanging wall and its corrugated edges secured to the crenellatededges of the inside'walls of the headers, a series of fluid ductscommunicating in parallel between said headers being thereby formed.

6. Cooler comprising a cooling wall having a smooth exposed outer faceand shaped to form a stream-line body, inlet and outlet headers forfluid to be cooled extending from front to rear of said stream-linebody, and a corrugated wall secured to the inner face of said coolingwall and between said headers,

the corrugations formingV a plurality of transverse fluid ductscommunicating in parallel between said headers.

Dated this 11th day of October 1930.

i ROBERT JARDINE WATT.

